The freshman Republican, who said his struggle with alcoholism "led to an extremely irresponsible choice," is facing calls from Democrats to resign. But following Radel's apology and decision to seek treatment Tuesday, House Speaker John Boehner said in a prepared statement the issue is between Radel, his family and his constituents.

Radel isn't the only politician who's been waylaid by substance abuse — indeed, the circumstances of his situation appear to pale next to the drama unfolding in Toronto, where the City Council voted to strip Mayor Rob Ford of his power Monday after he admitted to smoking crack cocaine and driving drunk.

While Radel's fortunes are undoubtedly damaged, other members of Congress have been able to win re-election after public struggles with alcohol and drug problems.

Here's a list of some of them and how they fared:

Rep. John Sullivan, R-Okla. (2009)

Sullivan, a member of Congress for seven years at the time, took a leave of absence in May 2009 to check himself into the Betty Ford Center in California for alcohol addiction treatment. He returned in July and sailed to re-election in 2010 but lost the 2012 Republican primary in the Tulsa-based 1st Congressional District.

Rep. Patrick Kennedy, D-R.I. (2006)

The son of the late Massachusetts Sen. Ted Kennedy pleaded guilty to driving under the influence of prescription drugs after crashing his vehicle into a U.S. Capitol barricade in May 2006. Kennedy, who had been open about his problems with drugs and alcohol prior to the incident, entered rehabilitation shortly after. He checked into rehab again in 2009. Kennedy announced he would not seek re-election in 2010.

Rep. Bob Ney, R-Ohio (2006)

Ney resigned from Congress near the end of his sixth term in November 2006 because of his involvement in the Jack Abramoff lobbying scandal. He blamed his addiction to alcohol and checked into a rehab clinic before serving 17 months in prison for corruption.

Rep. Mark Foley, R-Fla. (2006)

After sending sexually explicit online messages to male congressional pages under the age of 18, Foley resigned from Congress in September 2006. Days later, he entered rehab in Arizona to treat his alcoholism and other behavioral issues.

Rep. Karen McCarthy, D-Mo. (2003)

McCarthy sought treatment for alcoholism following a March 2003 incident in which she cut her forehead after slipping on an escalator in a House office building. She initially said she would not resign, but in December of that year McCarthy announced she would not run for a fifth term.

Rep. Phil Crane, R-Ill. (2000)

Crane, then the most senior Republican in the House, checked into a Maryland rehabilitation center in 2000 following an intervention from family, friends and fellow lawmakers regarding his drinking problem. While the episode may have cost him the chairmanship of the powerful Ways and Means Committee that year, he remained in office until losing his 2004 re-election bid.

Rep. Frederick Richmond, D-N.Y. (1982)

Richmond, a Brooklyn-based Democrat, resigned from Congress in August 1982 after pleading guilty to tax evasion and marijuana possession. The four-term congressman admitted to possessing several marijuana cigarettes obtained from members of his congressional staff.